SUMMARYThe study aimed to establish the common reasons for non-adherence to drug treatment among breast cancer patients at the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria over a ten-year period (Jan 1993 -Dec 2002). Patients' adherence and reasons for non-adherence to chemotherapy were evaluated using descriptive statistics. Two hundred and twenty-five breast cancer patients including 199 females and 6 males with breast cancer were recruited. 12(5.3%) patients had Stage I disease while 126 (56%) were in stage IV. The non-adherence rate was 80.9% and 111(73%) of the non-adherent patients were eventually not seen again. Of the one hundred and one patients who gave reasons for non-adherence, 45% complained of financial difficulties; 18% thought they were well enough; 15% were fearful of subsequent operation and 11% were unable to further bear the drug side effects. In conclusion, the study demonstrated poor economic status of the patients as one of the major reasons for non-adherence to cancer chemotherapy in Nigeria. Government subsidy of breast cancer treatment, improved health education and advocacy complemented by home visiting to encourage hospital attendance would be required for better adherence to chemotherapy.